Fiber optic data links have become commercially important to meet the high bandwidth and distance requirements of computer and telecommunications network technology. An alignment problem exists for optical fibers in disconnectable or pluggable connectors, particularly in harsh environments where alignment must be continuously readjusted to compensate for external shock effects and environmental factors of temperature, humidity, etc.
Some attempt has been made to address this problem by placing extremely tight mechanical tolerances on parts within optical connectors, which are statically supported in a connector. Tight mechanical tolerances increase cost and make the connectors difficult to manufacture. This problem is especially acute for the optical transmission lines arranged in a parallel array of fibers, for which a connector must passively compensate for tolerance runout across the array, i.e. variations in the spacing between the fibers in the array, in which the array's alignment must not be affected by environmental factors of temperature, humidity, etc. Even when passive alignment is achieved in some cases, the repeatability of the alignment in a pluggable connector, and the effects of harsh conditions, may be inadequate maintain alignment for some applications.
Conventional connectors attempt to obtain low optical loss at their optical interfaces by placing tight mechanical tolerances on the connector parts, which increases costs and causes manufacturing problems--even for connectors of single fiber transmission lines. The connector tolerance problems are compounded for connectors of transmission lines having an array of optical fibers.
Even when passive alignment is achieved in a connector, such alignment repeatability in another connector may be insufficient. Maintaining the alignment in the same connector may be impossible under extreme environmental conditions.
The prior art includes:
1. D. Hardwick, Polytec Optronics Catalog, Polytec Optronics Inc., Auburn, Mass. 01501 (1992).
2. P. Neely, "Electrostrictive actuators offer nanometer scale motion control", Fiberoptic Product News vol. 10, p. 23 (1992).